1. Field of the Invention
The present invention relates to a lift control device, and more particularly to lift control device for a roller shade.
2. Description of the Related Art
The closest prior art of which the applicant is aware is disclosed in U.S. Pat. No. 4,433,765 to Rude et al., filed on Sep. 13, 1982, entitled "Spring Clutches". However, the springs are separately mounted on a limit rod, and the lugs for each of the springs has to align with each other so as to be fit into the slot of the cap, thereby making the assembly more difficult. In addition, the inner wall of the slot of the cap only contacts the lug of some of the springs, and cannot contact all of the springs such that the force exerted on the springs is not evenly distributed, thereby decreasing the retaining effect between the springs and the limit rod such that the force is concentrated on the springs which contact the cap causing elastic fatigue during long-term utilization, thereby greatly reducing the lifetime of the springs. The present invention has arisen to mitigate and/or obviate the disadvantage of the conventional spring clutch.